Drive mechanism for manually operated sheet winches

ABSTRACT

A multi speed manually operable sheet winch for use on sailing craft, having a direct drive and two reduction gear ratios arranged to drive a drum. The gear changes are effected by reversing the direction of rotation of a crank handle, and the direct drive is effected through an operating member which can be used to disengage the direct drive manually while the first reduction gear ratio is being used, so that a further reversal of the crank activates the second reduction gear ratio.

O Unlted States Patent 1 g [111 3,802,665 Fawcett 1 Apr. 9, 1974 [54 DRIVE MECHANISM FOR MANUALLY 3,728,914 4/1973 Guangorena (74/812 OPERATED HE WINCHES 3,711,065 1/ 1973 Lawrence......

3,656,596 2/1972 Morgan 254/150 R X [75] Inventor: Derek James Fawcett, Havant,

England Primary ExaminerRichard E. Aegerter [73] Assignee: Lewmar Marine Limited, Assistant ExaminerH. S. Lane Hampshire, England Attorney, Agent, or Firm--Bacon & Thomas; Jerry [22] Filed: Nov. 11, 1971 hlebeau V H [21} Appl. No: 197,883 [57] ABSTRACT A multi speed manually operable sheet winch for use [52] US. Cl. 254/150 R, 74/812 0 il ng r ving a irect drive and two reduc- [51] Int. Cl 865d 17/30 tion gear ratios arranged to drive a drum. The gear [58] Field of Search 254/150, 186, 187, 150 R; changes are effected by reversing the direction of ro- 74/812 tation of a crank handle, and the direct drive is effected through an operating member which can be [56] References Cited used to disengage the direct drive manually while the UNITED STATES PATENTS first reduction gear ratio is being used, so that a fur- 3 599 937 8/19, Caner 254/150 R ther reversal of the crank activates the second reduc- 3:682:442 8/1972 Baldwin gear 3,618,896 11/1971 Bewley...., 254/150 6 Claims, 13 Drawing Figures 1 1 i H LE I r s m, 3 /2 5 DRIVE MECHANISM FOR MANUALLY OPERATED SHEET WINCHES BACKGROUND OF THE INVENTION The invention relates to manually operable sheet winches for controlling sheets of sailing craft in which the gear ratio between a crank handle and a winch drum may be increased in three successive stages during the winch operating cycle. In particular the invention relates to means for changing the gear ratio during the operating cycle.

Known winches suffer from one of two defects, namely either the gear change is complicated and time consuming, or else it is automatic upon drive reversal (or drum overrun) so that inadvertent loss of direct drive can result during tailing.

SUMMARY OF THE INVENTION The invention provides a multi speed manually operable. sheet winch, having a direct drive and two reduction gear ratios, and comprising a drum, a drive spindle and a handle arranged to drive the drum via the drive spindle by means of two gear trains, one of which has an odd number of gear stages and the other of which has an even number of gear stages, which gear trains are connected to the drive spindle by unidirectional drive means, and a direct drive arrangement comprising a manually disengageable unidirectional drive means between the spindle and the drum whereby the handle may be connected to drive the drum directly in one rotational sense.

In one form of the invention the manually disengageable unidirectional drive. means between the spindle and the drum is formed by a mechanical connection (e.g. a ratchet arrangement).

In another form of the invention the manually disengageable unidirectional drive means between the spindle and the drum is effected by frictional engagement (e.g. carriming rollers).

In one arrangement the manually disengageable unidirectional drive means is operable by means external of the spindle. I

With this arrangement the manually disengageable means may comprise retractable pawls attached to the spindle, and disengageable by means of a member rotatable on the spindle.

Alternatively the manually disengageable means may comprise pawls attached to the'drum, and disengageable from a track attached to the spindle.

In another arrangement the manually disengageable unidirectional drive means is operable by means partially within the spindle.

With this other arrangement the disengageable means may be operated by a shaft passing through the spindle, and capable of retracting pawls attached to the spindle by rotation of the shaft.

Alternatively the manually disengageable means may be operable by a push rod extending through the spindle and capable of retracting the manually disengageable means.

The manually disengageable means may be operable magnetically (i.e. by the relative movement of two permanent magnets or one permanent magnet and a soft iron core).

It will be appreciated that the invention is concerned with means to effect a first gear ratio change operation by reversing. the direction of rotation of an operating crank handle. In the course of operating the winch with the second gear ratio engaged a control ring situated on top of the winch drum is partially rotated to disengage the first gear ratioso that when the direction of rotation of the operating handle is again reversed the third gear ratio is automatically engaged.

BRIEF DESCRIPTION OF THE DRAWINGS A specific embodiment of the invention and some variants thereof will now be described by way of example with reference to the accompanying drawings, of which:

FIG. 1 is a cross-sectional view of a transmission system of a winch;

FIG. 2 is a section on the line AA;

FIG. 3 isa section'on the line CC; and

FIG. 4 is a perspective view, showing a pawl actuator ring positioned on the head of a winch drum.

FIG. 5 is a cross-sectional view of another embodiment.

FIG. 6 is a scrap cross-sectional view of a variant of the top of the winch;

FIG. 7 is a cross-section alongthe line VII-VII in FIG. 6; a

FIG. 8 is a scrap cross-sectional view of another variam of the top of the winch;

FIG. 9 is a cross-section along the line IX.--IX in FIG.

FIG. 10 is a scrap cross-sectionall.view of yet another variant of the top ofthe'winch;

FIG. 11 is a cross-section along the line XI,XI in FIG. 10; g

FIG. 12 is a scrap cross-sectional view of still another variant of the top of the winch; and

FIGQ13 is a cross-section along the line XIIIXIII in FIG. 12.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT As shown in FIG. 1 a winch drum 8 is rotatable by a crank handle 4. Whenthe winch is operated with its first speed engaged there is a direct dirve between the operating crank 4 and the drum 8. Centre drive spindle 5 is clutched to the drum 8 via ratchet pawls 2which are pivotally attached to a collar 3 fixed on the drive spindle 5. and which are engagable with an internal ratchet track 6 which is integralor rigid with the drum. The ratchet pawls 2 and track 6 will lock the drum to the spindle 5 when thehandle is rotated in the clockwise direction.

The gear reductionsystem for the second speed is via a pinion l0 whichis coupled to the spindle5 by ratchet pawls l2 and teeth 13. Pinion l0 meshes with an idler wheel 11 which in turn'meshes with an internal gear 16 on thedrumr The gear reduction system for the third speed is via apinion 9which is integral or rigid with the spindle 5. Pinion 9 meshes with a gear 14 which is coupled by a ratchet system 17 to a pinion 15 which in turn drives the internalgear ring 16 via the common idler wheel 11.

To operate the winch with the first speed engaged the pawl actuator ring 1. is rotated in the anti-clockwise direction tothe position shown to allow the pawls 2 to engage with the ratchet track 6. When the crank handle 4 is rotated in the clockwise direction the drum 8 is locked tothe spindle 5 and the drum thus rotates at the same speed as the crank handle. The ratchet systems between the spindle 5 and the gear 11 and between gears 14 and 15 are phased to rotate in their free directions and thus the rotation of the drum is controlled by engagement by the ratchet pawls 2 and track 6 which lock the drum to the main spindle.

To operate the winch with the second speed engaged the crank handle 4 is reversed to rotate in the anticlockwise direction. The ratchet pawls 2 and track 6 then free the drum from the main spindle while ratchet pawls 12 and teeth 13 engage the pinion 10 with the main spindle which in turn drives the drum via idler gear 11 and the internal gear 16; The drum thus continues to rotate in the clockwise direction but at a lower speed relative to the crank handle while the rachet system 17 of the third speed overruns.

While the winch is being operated at the second speed the pawl actuator ring 1 is rotated partially in the anticlockwise direction to retract the pawls 2 from the ratchet track 6 in the drum.

To operate the winch in the third speed the crank handle 4 is again reversed to rotate in the clockwise direction. Ratchet pawls l2 and teeth 13 disengage pinion from the spindle 5 and since pawls 2 have previously been retracted the ratchet system 17 couples wheel 14 to pinion l6 and the drum is now driven via gears 9, l4, l5, and the common idler wheel 11 meshes with the internal gear ring 16. The drum thus continues to rotate in the clockwise direction but at a still slower speed relative to the operating handle.

When the drum is not being driven it is prevented from rotating back in the anti-clockwise direction by any two of the three ratchet systems being engaged in opposition to each other.

DESCRIPTION OF MODIFICATION FIG. 5 is similar to FIG. 1, but shows a development of the winch according to that embodiment. Like reference numerals are used in FIGS. 1 and 5 to identify equivalent parts. It will be seen that the drive between the drum 8 and the gear 11 is now transmitted through a free wheel device 21 and a gear 22 which is engageable with a track '23 substantially above the base of the drum 8. At the top of the winch the ribbed pawl actuator ring 1 is replaced by a flanged operating disc 24. It will be seen that the time taken to change speed for both speed changes in the cycle will be limited to the momentary pause required to change the direction of handle rotation, since manual selection for disengagement of the first speed direct drive clutch may be effected whilst winding in second gear. A further advantage of the system is that the manually disengageable unidirectional drive clutch between the handle and the drum, allows the drum to overrun during the sheet tailing operation without disengagement of the clutch or driving the handle overspeed.

DESCRIPTION OF VARIANTS FIG. 6 shows a variant of the invention wherein the direct drive between the spindle and drum is effected through frictional engagement of camming rollers 27.

In another variant shown in FIGS. 8 and 9 the pawls 2 are pivotally connected to the drum 8, and indentations are formed in the spindle 5 equivalent to the track 6 on the first described embodiment.

Yet another variant is shown in FIGS. 10 and 11 in which the handle 4 has a boss 28, and there is a plunger 29 which may be pushed downwardly throughthe boss to urge crank members 31 and 32 into engagement with indentations 33 on the inside of the drum 8. The arms 31 and 32 are urged outwwardly into engagement with the indentations 33 by means of springs 34, and may be retracted from these indentations when the plunger nib 35 is driven between them. FIG. 11 shows the plunger at an intermediate position as it is about to pull the arms out of engagement. There is a groove 36 just above the nib of the plunger. to retain the arms 31 and 32 in their retracted positions.

Still another embodiment of the disengagement mechanism is shown in FIGS. 12 and 13, in which there is a rotatable knob 38 on the boss of the handle 4 and this knob turns a cam member 39 which draws the arms 31 and 32 out of the indentations 33 in a manner analagous to that described with reference to FIGS. 10 and 11.

I claim:

1. A multi speed manually operable sheet winch, have three drive ratios, and comprising: a drum, a drive spindle and a handle arranged to drive the drum in one sense of rotation by means of any one of a direct or high ratio drive arrangement and two reduction gear trains of differing ratios connecting the spindle and drum, one of which trains has an odd number of gear stages and the other of which trains has an even number of gear stages, which trains are connected to the drive spindle by unidirectional drive means oppositely directed with respect to the drum, the drive of the drum in the one sense of rotation successively in the three drive ratios being achieved in low intermediate and high ratios, or vice versa, successively by rotation of the handle in opposite senses of rotations successively, the direct or high ratio drive arrangement comprising selector means on the winch operable manually between an operative position in which it permits drive transmission through the direct drive arrangement directly connecting the spindle and the drum for driving the drum in the one rotational sense, and an inoperative position in which the spindle is disconnected from direct connection to the drum.

2. In a multi speed winch in which successive low, intermediate and direct or high drive ratios between a drive handle and a winch drum driven in a single sense of rotation by the handle, are achieved successively by rotating the handle in successively opposite senses, the improvement comprising of providing a drive train for each of said drive ratios, and a manually operable selector means, two of said drive trains being connected at all times by undirectional drive means beween the drive handle and the winch drum, the unidirectional drive means of one of said two drive trains being operative to drive the winch drum in said single sense of rotation only when the drive handle is rotated in one direction, and the unidirectional drive means of the other of said two drive trains being operative to drive the winch drum in said single sense of rotation only when the drive handle is rotated in a direction opposite said one direction; the third drive train comprising the direct or high drive ratio being selectively connected between the drive handle and the winch drum by selectively operative drive means which is operative for driving the winch drum in said single sense of rotation when the drive handle is rotated in the direction of said single sense of rotation, the said selector means being operable manually between a first position preventing operation of said selectively operative drive means and a second position wherein said selectively operative drive means is operative.

3. A winch as claimed in claim 2 in which the selector means is disposed partially within a space formed between the drum and the spindle.

4. A winch as claimed in claim 2 in which the direct or high ratio drive arrangement between the spindle and the drum is formed by a unidirectional mechanical connection and the selector means is operable by rigid with the spindle by said selector means. i 

1. A multi speed manually operable sheet winch, have three drive ratios, and comprising: a drum, a drive spindle and a handle arranged to drive the drum in one sense of rotation by means of any one of a direct or high ratio drive arrangement and two reduction gear trains of differing ratios connecting the spindle and drum, one of which trains has an odd number of gear stages and the other of which trains has an even number of gear stages, which trains are connected to the drive spindle by unidirectional drive means oppositely directed with respect to the drum, the drive of the drum in the one sense of rotation successively in the three drive ratios being achieved in low, intermediate and high ratios, or vice versa, successively by rotation of the handle in opposite senses of rotations successively, the direct or high ratio drive arrangement comprising selector means on the winch operable manually between an operative position in which it permits drive transmission through the direct drive arrangement directly connecting the spindle and the drum for driving the drum in the one rotational sense, and an inoperative position in which the spindle is disconnected from direct connection to the drum.
 2. In a multi speed winch in which successive low, intermediate and direct or high drive ratios between a drive handle and a winch drum driven in a single sense of rotation by the handle, are achieved successively by rotating the handle in successively opposite senses, the improvement comprising of providing a drive train for each of said drive ratios, and a manually operable selector means, two of said drive trains being connected at all times by unidirectional drive means beween the drive handle and the winch drum, the unidirectional drive means of one of said two drive trains being operative to drive the winch drum in said single sense of rotation only when the drive handle is rotated in one direction, and the unidirectional drive means of the other of said two drive trains being operative to drive the winch drum in said single sense of rotation only when the drive handle is rotated in a direction opposite said one direction; the third drive train comprising the direct or high drive ratio being selectively connected between the drive handle and the winch drum by selectively operative drive means which is operative for driving the winch drum in said single sense of rotation when the drive handle is rotated in the direction of said single sense of rotation, the said selector means being operable manually between a first position preventing operation of said selectively operative drive means and a second position wherein said selectively operative drive means is operative.
 3. A winch as claimed in claim 2 in which the selector means is disposed partially within a space formed between the drum and the spindle.
 4. A winch as claimed in claim 2 in which the direct or high ratio drive arrangement between the spindle and the drum is formed by a unidirectional mechanical connection and the selector means is operable by means external of the spindle.
 5. A winch as claimed in claim 4 in which the unidirectional mechanical connection comprises retractable pawls attached to the spindle and disengageable by means of the selector means which is rotatable on the spindle.
 6. A winch as claimed in claim 4 in which the unidirectional mechanical connection comprises pawls attached to the drum, and disengageable from a track rigid with the spindle by said selector means. 